SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3874f26d458860f70b54999539499bdd933c17e21a00582320da0fdb0cad8a48' 
  AND token = 'Wz0VFM85PV5zJMVHU+TFMpaQLxJlI5gwKTLLE+lYtrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}