SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ffc62f1fbe252748037e60ce022754769ca87273a9a375b17cdc9b32e608f5d' 
  AND token = 'ZRgsOEBxYxANTuqs/dKBKArWFczECYDWjUz9it+dLZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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