SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af3c6825fe0292c3d959f907dc8755b853621116d5206cd7e0bb6faa27465dd4' 
  AND token = 'VxqHaSTC0ia+kelKX/J/Y3vjGExHfa6CbEMEMXLizjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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