Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6392be6745cb137f9438ce6f06161304a6ed03a03d40ec2582e0695f3ab2053' 
  AND token = '//fpXY9ipTeegrJPJf4IynsuBP/BUK0WcvX04v2czmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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