SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d23d863bee43f553db2b40f4d0b27901a4cfddda6797517d3cf9ea6abc1b1ac' 
  AND token = 'BeYXANUIfnmK6aHzqGY3Q0MuZGi/XJ0c4xHvT0M/jkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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