SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd20256eaef2ce6305b3173199fa1c48e16b56fffa643b195e49b9e5649e413f7' 
  AND token = 'k0jLFyScQHrmMzpIHgOqUoqxeOtqeV7ybv70ZhP2c9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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