SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f33341cf1f64a33f97195614e33904b41ea969f15827b35cb42d63981f5ac05' 
  AND token = 'CjE2EVmLqnZmlfouaiwuDpzJFnwAayNovF8NVPs/fyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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