SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cc541d1bf46d47668f64b685b577524dbcf49ef28099db747e31b8e4020179a9' 
  AND token = 'brgWBfwOFwdVz6q2Y+8K27Ii6OzUWzFFYIzrxDZulA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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