SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7175beac2c42b5642da88e2d48b27c7aea526f00a6ad3e8c058319d742d22523' 
  AND token = 'd9WdVxwdUgatKF4xwhnWIaNMS2fP54thQ89dnUmrGHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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