SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdc43fe8627e5c5cc6faadbfe042dd982863b81b8e001a9be8073c6522bda1cd' 
  AND token = 'rQtS7GEZma5RbGBitHTJKB8BfHsTGld5JgsmHfFlBVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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