Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b44f2d8dbff9821e2c0ecbd5ca32b2d7aacf5fffc3bff7cce16f8069daccc512' 
  AND token = 'PFXVxt3kYofrZEjk4da1vrSGKGXWkhEZbDoxmEs/h8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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