SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '466940e93baffa344c9516966590307ad0b8c31e4326eb46b1455088c2fdb2c2' 
  AND token = '/2W0G4FgyIyeX60EGToNyYzX/Mi5wHW+xWKFqaghSp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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