SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5857a84ba99753d6774ba5aff6764804be64c12f3068e79d544e0e64274897e2' 
  AND token = 'KJVB4jD+lzzftcASjZh5QUCMQufC5DJLgMouLImUeAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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