SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3195622017b97f7a9b4f60a43ed474812f66478165ecf2ff55ec3d22bb4d9288' 
  AND token = 'hWFgpNTTrLww5Y5jKEqMh2pwyI7LuU2ksObzZdQ+2RQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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