SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '452ce638802c27074c7d7dd3a1782a3eaf6c36f6d926ff162e15765b979cb717' 
  AND token = '+fVsKvHRTmgf4fB14GCKVPGJ9B2xpRMbr64Lvf3Jq7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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