SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2139cc0ec00890d5ba729f488fa6694702f0fc3f7ff3c27d2aca675b9395185a' 
  AND token = 'AZslnSKu/fZbfft/2gbifKNEcRdgCxJYASRGtwe18oI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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