SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2fbcd8c9ebe6a3b104c99b2d17a806497438ee9c808c94ecffddc5179977d82' 
  AND token = 'tLSnpL0X8zpw5c4oBkqmodVxue5VipbrEhTvGcdfamA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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