SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afee9b3211fe225864ec98d879d5a22c7db8841ec51672e5e735c37c8f6e434d' 
  AND token = 'wsjVd9ZfCjRLUqvoGNWOKZ/6dVAbcNqa7VMh4WURsPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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