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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cea32c950f2f9c9b5c92e28b023a639fe4b2f43f42adf6f0827433920b33ba6e' 
  AND token = 'u1dUHjhA5ZyM0Ba6PjPHPcWv578ExlZUJtXrHIZiYqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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