SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c79d4eba4d08644e463a783216aaec0058860311633976a4bdb0349d30bc69d' 
  AND token = 'npFgeoUuPKuNWbh/dCtZeoqtyWAz8ONL67P+0pz2CVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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