SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0d86b6f6330cc84269a140b847a5b576b2784e6289c543324ed3dac2ff824eaa' 
  AND token = 'bg4c6qhhmjTUHKfGvzSajbSHLk0nMylglPXr7X2djPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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