SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7076ffc3ce9d49a4fc8d00a954dd8baec5dc7c6d43241fd77afc376f6d880391' 
  AND token = 'bAFrZMS34nXhEdXbzTKZ6NxTMiOHsGvbkZgTvAOpqxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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