SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8af67aa1ce8c80098130823b8ee7146deec254b0bc800f54c3a29513d172b204' 
  AND token = 'rxl5xKHoYhL39QDXe0u5/a37cyrMkEwFRYrPUcGzBwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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