SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '942e3027a885af8c24cc23d6753c0bbafe241b98d9c843a4b16870947d496e41' 
  AND token = 'jzrvq3oP/aBYFUmRPmlinr96kUSorystHgqvBGz2ag0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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