SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4459b3898c41c7b859433fd244bc3880fc697d421814b245698f41116b2cad9b' 
  AND token = '19ZkInjM6dFUXXezYxaK8iHtqFihu3LOr94H66RaNBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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