SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3a99d9abf4fa7f5c5c593ffc9abb7198fdc4e7040bdca352778cf68beed5e335' 
  AND token = 'DrlqP453XkTbrMHKhMim5jhN9/Y6FPtW+x0wrSd/lE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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