SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '645dd07b8cae9673a37c62c85f380bdd6e069978f75156d1de9d1f68f785208c' 
  AND token = 'gkz/qBPlWKSudjOqYCBnCNU5YgLLbx+iOaY5v8eZpGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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