SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0807321857770f78073b30cf2ef676fea84c314a4e3f4e5eb553bcbbbcd8ebd8' 
  AND token = 'hDkpv+mSO13acrpLGELyL9t9SznHdDBlAiKOydG9mis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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