SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ac7ba9f0fe62b910c443fcde6dca30293ef72773db8e1b250ab4e25e838edda' 
  AND token = 'VShmJTgFJOlvklquwvO4GM/JHLxNaEZiLRTQySGYibM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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