SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42177205cfee82eba28839b546cc3d0131e8238b26cc13107efcbfdec56d7286' 
  AND token = 'wla3Y7reIrAGEzN+pTKpaWtecLWq3iMH83SG/8cyxKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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