SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebc24ded4b9cc6fb00397131f80d147f412e86955fe963c2c845a12809dbcd94' 
  AND token = 'qeB3D49HaD0EIq/yspz35bsRoxERBDjj723ox83BT8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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