SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '102d65fce79a6f5900519fd17f98bb1fc9a95625f6b45df18a77d853b3c1b295' 
  AND token = 'IByxHOu2R/YbZaXaJVwNtl2RjwLSC/P4eXul9QxJbUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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