Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6f51e282e0a9df95475028db945a161f666be642dafcb5a8adefd27af852b2a' 
  AND token = 'SCvfK3DcccvXerr1niwEkau8ND6P4xNq0+UNqG9NOnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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