SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d66fc96c8dd8d643d48768ea1b108fc27982c50abd1a169e8b7c58aa89a2309' 
  AND token = 'Hm+XJbgQ8TCi8rEeXqhcSGvtq0aztQOVDcDmq/dmeNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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