SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cf30a77aeed56ecd36a90ef5de1f454c2c89664cf0fcd8e92b90314aae1c2cd' 
  AND token = 'Oja8ULkMFnDz2VPZYwcEO5HGhDv7skYA5xoTBtsK3A0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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