SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8848449cd6f8082fb26dd8bce6c722045e3f605f373c457cb03c5f1dbba12288' 
  AND token = 'FRMeEYUWvdQtHe4TZPuJpiRXqqPvS5rRnoow4MZ+aaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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