SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80894c8b23aeca068e68d669af249f29716b19aa0507c1dbf5170b5d2cab0766' 
  AND token = 'H4thOd9enudkfsRVJnmzhcBAelyo0+uskwDjI7qxAWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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