SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffd5f02f7c8b22e37e888052ce8110d22fadc5041427d6c2be92f9297d5d8376' 
  AND token = 'nFfun5HHTZ+xXT5v7vJFLNip+5W8gf0WZSnvFp6ccqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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