SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8ffa715465299c11811aa80129fe86eabc968077b324df931b9cd67adb20312' 
  AND token = 'cCyY5yyI2brHBQWEft5LjUStF5lDlHDgSzPzE1VTzw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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