SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c01ebd91989fa67dfc574f9a9e418ebf6ab2210dd03bd6f52056c17b8b08bf9' 
  AND token = 'NjD6bmWMEku5BGwNjGaj65Hv3pcmnNhBwd0TN2XMGUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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