SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b549ee80ec9d8e7449206fc790bbb0223684b376b5df572eaa432b0c8253cab' 
  AND token = 'B2MTuo6gOq5G8U8R/Vw1uGAQXh3mVWsJXhnW0IZttUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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