SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '221636d5ba6f91cfbe1752b79976965b21a86fcbeb466e4a7ed352fc0212278f' 
  AND token = 'UO+PvQogVDS73oBqWuE6GB/o6hD0GYI9hqTMl89zeMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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