SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c9925a92a169cad10329bb0488fbf350bac6f0237b3c29442a7e01c40d12028' 
  AND token = 'm8t7WjHAIpudDUJ9Ve0R+T72mHjF3EqjAQWNQsME+qs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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