SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dd7602217a4a8e36d478c9d843e5091096f046b1ca34420f0742d74f0b315a8' 
  AND token = '/q/yV6AP1IHPylkXYPuljbGI2UOUxv86hDgZ3b4k/Aw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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