SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fe710600a4514db816572f303c15e034908a2467b115b2e693b4475fd8699d8' 
  AND token = 'qbbAHoDuiFTlAwjNRhsGgWXaJ0cwxRfZwx4vfFW4oa4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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