SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35ab5d9b9f88c383d1360dca86aa0bf90a9d108fed411c843a4d5eb0b7bc4014' 
  AND token = 'pOHzdVygqFkauPKJVJJOWWxmCT3gZneatmUwH+gNEX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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