SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5f08ada160fcc1df9073d77389178b2c98150303b0b7af1a69793dafec2f061c' 
  AND token = '2P9gfSgINtmjdCOIE8hGVTYw6jyrH7OZMM58JBeE6FI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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