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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5bd9f6aef4f1f06c6bd42cbdb6f8bde827e61afeb2b1ba2afee72bfa1c6e223' 
  AND token = 'OyT8kRtZ9xlwx3RIZN6ct5++UsObwmiqjXm+8QpJvVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}