SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a40d4170bf6d1aa3488d8dad4e2c986040e08520d460429d94048a0d0c6a3957' 
  AND token = 'ZzecLeuxKF/T7RZ4lu8Ail97FCNKJ/5X4fx1oEGfkZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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