SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ab392f6948d1790c76d5dfbad75cf80b13bb468eb0f21081d0b7e964abfc325b' 
  AND token = 'LIRzh4HOHXRPas+bFK22bFgZ0Gfd5s179aSMv4Whtiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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