SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d55efcc98ebc67fbbfd3b480a35a345f56caa0de90497b1458ed02edeeb63e7' 
  AND token = 'CkSSkK7e5mBIOZoMQCbcs+OtV1SbfSL98sqPHhNrX0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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