SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24f793af977bec489a194948e811d333e42dc2828f37f298b99dd905aea35d18' 
  AND token = 'ikz16tZ/dPXoKhDjL/yDGOQBJcBnv1i6NezIKGxIsBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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