SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f0f14e611fd885dac4c084b42941fa7012bc82c90dd4d99407638beb7b7b175' 
  AND token = 'wqq8TzhEHWvzvI6IYDMZHAWqRkCd0DpnMbiDxNPQ5Z0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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