SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1505c8c070244fd270568fec6b96263a547b8e0239477005a6baff4e7679813' 
  AND token = 'Xxkcorpivf5aI954FSkk1FmbNKVyulzyuXVmE9HxkEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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