SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd6f565b8d821d0a0a116fdce1026dfe265646a699af740fc31f4aed91735a511' 
  AND token = 'NeKXGplbRcQWPBHhxFuixuzPoTSlX6U4je1EWI0RtcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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