SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2a612604b8fd0c488ead1469b1b7a21b5427bf87eb22ed663235518dfb208ed' 
  AND token = 'aBg+EZoS1E0Oeo8xFukJXt//YOKuN/lP8NbW5ayLUHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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