SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0cd634261fa08b5734f53ffa4e4cefa1837c946bbd482cb5e0476fc91b03a1d' 
  AND token = 'qeiqXVaodW4f83zFoRmAy/0X7kEoZTOZA8RYwzc3i0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}