SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e048b339b079e479b817b78cd24595101da65aa58a24478bfde715c215d09cc2' 
  AND token = 'Iy4AqXvSD2bQAxJAjSB2r9qZ0QlPehJ8ATBYm/QTQwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}