SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '396660c9e9ec60d390cac1095bed075554ec7ca186be32d2cf8c952adb1af143' 
  AND token = 'rFevTw4pdYdmcT/Rcl/v5eGBdodraoilzEU7rsEG3sA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}