SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ad901e7455f034d352f442dd2c1cc253d2c25face74bf6609265486dd340f57' 
  AND token = '01u47gROJKpw7uCDIkbf7DZ/LNkopkORxugm0gvZQ0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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