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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4feb869074483b48f8bbacefbb7658b53d7f7d2bd1581b6ccbc7565fc649c55' 
  AND token = 'vLwTpvgyzUlUQ3pwNvBRZQcxgFGtLGKW90cWx7b+tgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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