SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '19d7748cb848f9bb625f1e44433e583a38c7cd113dea4999d12496db496d9dc7' 
  AND token = 'Ja6cP8HEDDlzi67YMBCwY+vea90ZBDogw3VntLiLk2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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