SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7af09852823baae5b96b9036c6d5731c6d5ea8410cfd3740d8b41be0812d0cfa' 
  AND token = 'g7RTioACmPgZwXz/lTlXN1ypQR6X/WaOuVw+RjPlgdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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