SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '338ed23cfda54e3eb9d467dcd63ec6c5fdb052b33541885f7beb8544d5967ebc' 
  AND token = 'vCDxwImsO6phMaF8v5mZsINfHkZZFMWP8Gs1bPKjNUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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