SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c94a45dc25cd62ca48ab595197acf9a0766c0bec46ea831bdc264c294b56527' 
  AND token = 'gCDOdrp18E9DC4tZ+jRUkINvFR0Bg0+7IYxnhXlJ6Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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