SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8d97a03a4142cda9b8cd32e6e03f2fd4aeb3ec5a9382be2a9e3548d8ffce87e' 
  AND token = 'Fkd1EJEvE7x7x7Yr6hNkL0ww/weZOtJP+lsX5XFJxFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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