SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd3129b35453691b61b014542b1f36f14dbe6174c4fc21775d395c260d29fd28' 
  AND token = 'naDUmgwgvbvvwVzb13bEkUmJH2iFVKpqNIo9fljLoRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00118

JSON explain

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