SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09491cf235a616d8f1e06361bc660dce6f174c173c6801cc73ce42c5923692de' 
  AND token = 'eBVZlR12PtxTiBxdmBE3vczXg2ab5jhAtFUOCsgayBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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