SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a74942a8490932c24b7f31ccbf0186a80f597a67d4de58e9efca0cf5b8eb5263' 
  AND token = 'jtuVpbPZwGDwoYf4mXPqSwGzQVARcUIKV7xsCFn0RXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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