SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '49612fb1cb7a4052d5347e529b86615acab976b738f1cb54c94f03542433fb15' 
  AND token = 'BrUJ30hDLudUXXOrnbbQ0JEI0dGKmrDgX70gaUUCLYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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