SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b3a53f1c254bbfb32fd9e3eb7de375042009c91821965f529434693a6dd97b51' 
  AND token = 'GxApRmJ/KRc/HrxIClfn/RUhcc7FpdlNS3iMOmqFXkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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