SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5847060473c31a5590a90ee605b6e54636a71d742f4a16f229c9971dc9cf5b8b' 
  AND token = 'jQaS9Lh69VmpPnWpeRU60G/72ZYL0LJAknx7kzUt+Qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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