SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce912738a379539c3605098ee7ee071293f936d4de9a3541b716ad231e094eff' 
  AND token = 'wYTw2ko3enF1rA0C3LAiEwOEwTCKwn/QEPS0OQtzWtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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