SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9cd7e9c26b520727f046766564bffc82d51d65ea189c87ae229ff9606d62a7d3' 
  AND token = '8ea9zwF2IuinbVj4E6S1YdCl1uuSmKHiuqPkuxCmDaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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