SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5810ce880af1a78b0a24f6af12a3f705802285cdf1c2862b96aa1ebb90354e00' 
  AND token = 'misQ9J33eDdZ6U8VAccCkqDo0GNelzix5sZMyou9KXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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