SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0350849b609bd059ffc9587a7c9a2266e77205a1fb96f7799ab197de765ee48b' 
  AND token = 'W8+xZofrdJj+SedBg21lEAAoVjr9xIKCkul/dU/OSV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}