SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2d6f09462d56244b12c1abce377ade31cc94c60640bcaa7997b3c34c947e03d' 
  AND token = 'ZDCcGRGhfk4c8/pbBC4DFnHEoTbhKI7lK5WJDwq2iZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}