SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03befdffb301371963cb106e49eb8a36065d161a2f7827cf5feca9fa6f3be342' 
  AND token = 'd0IzK6FBSKx/KPHslTdfJlo7O2M8Cyh5p3IkTTUl3kc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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