SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3897165cbcc6c99e753157fa23c75c2542763e6d7f05d26cb6e93e005ab36db' 
  AND token = 'WiAU+e2iX82HUTzDWHDUDMB0pYwbke0Q42hjSp01dxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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