SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '602a59ffa3a15e503455221fd6b46ac510af73686d0bbd9e324c1e89edd4a683' 
  AND token = 'mqb4vuYtUWkUs4A7SBFWO+SMvhwD6rZoTi9Qzp++TyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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