SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb4560b48dd023926c4c4cfabf74db3cb0e3107bf333b3f70b602f388cde3387' 
  AND token = '/AhSkAVTmJVhQQzTWaTBYwqf2vPKuejRi9duwx6bsSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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