SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c15fc4353083bc76294d708c1dc24a1e4e2b2bf57a4207f67f265e0d30de070b' 
  AND token = 'ezPjs1IKo9VPSf/CDCXgJC18TcxJgnFpwHskCSRq3RU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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