SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2ecf908b52084c50addcd33ffcd3d33b6088163b0e7404c94953302ffd1e964' 
  AND token = 'olFNLRyXeMXH26Jb5ndPPuHi7Lv2Sz4BgDUpbnh1wjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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