SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40f99edd3605328b8deabc0cc32e8431c2d9fe19d8af580a4b312e12780efd06' 
  AND token = 'WiSajlvM/98CYfP7vtTv2XnwkRHAZspwnDHOzU8Ho2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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