SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a95208a43110279498191df86e57676366d838c12214e707156c18bb1240cb87' 
  AND token = 'H5AWhDlcrHUVA/hrfxKqXT2SB51yKhKJ8hgkm6Jex44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00084

JSON explain

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