SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53c458eaa9335dafec72296d566bd7524a43b924124fa39ee346632d1ec4130e' 
  AND token = 'hB3djbEuq/SxUWvwHhGGRJu41UUCx+hMuOISZv5VWSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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