SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a207d5489430e98ba1fc57184ed228b1d4975f41445ae1211c9d9fc7c3d0b7ec' 
  AND token = 'LNTcI7ys0sBrs2MLR0sWGzIqfsQhlnpSMfM9F9Pecog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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