SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1339052be6b35e4b5cec4446f23aaf1b0181d699cc6e8396216eeff812e628c' 
  AND token = 'ESoTLC7d1966Kfl7jKd9gKSstdYa6QyLkAlODiTVWCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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