SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a114d09492e01237e1aec5b4070d7655262ecb59f0c682f61498d52af849f4aa' 
  AND token = 'ScZZMCVZKz74XXbgUdvvJ3SMu0JgnCwBwd/mdjukvys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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