SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0dcb87f917d312c16e58a7ab3a9f59b62d9647c826afc6d551a50041a182128' 
  AND token = 'j4suvjgS2ST2qvQo4ZTa0GCJl0JI2KNpYDIM+XLkItk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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