SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec55b459c255ce3bb9da9bd320265a87c006f281121181217350284553db91ce' 
  AND token = 'JIKjObYbBg1AZcmwXhJdHemYKgGBoBpPd3k+QEg3EfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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